Tappet valve-motion for direct-acting engines.



PATBNTE'D JUNE 3o, 1908.I

D. J. OROURKE. TAPPET VALVE MOTION FOR DIRECT ACTING ENGINES.

APPLICATION EILED APR. 8,1904.

Za by y UNITED STAIESwPATENT OFFICE.

DANIEL J. OROURKE, OF CLAREMONT, NEW HAMPSHIRE, ASSIGNOR TO SULLIVANMACHINERY COMPANY, OF CLAREMONT, NEW HAMPSHIRE, A CORPORATION OF MAINE.

TAPPET VALVE-MOTION FOR DIRECT-ACTING ENGINES.

Specification of Letters Patent.

Patented June 30, 1908.

Application filed April 8, 1904. Serial No. 202,167.

To all whom it may concern.'

Be it known that I, DANIEL J. OROURKE, a citizen of the United States,residing at Claremont, in the county of Sullivan and State of NewHampshire, have invented an Improvement in Tappet Valve-Motions forDirect-Acting Engines, of which the following descriptiom'in connectionwith the accompanying drawings, is a specification, like letters on thedrawings representing like parts.

My invention consists of improvements in tappet valves, beingparticularly applicable to tappet valve motions employed upondirectacting engines, such for example as are used with rock-drillingmachines.

My invention will be best understood by reference to the followingdescription when taken in connection with the accompanying illustrationof one specific embodiment thereof, submitted for illustrative purposeswholl while its scope will be more particularly pointed out in theappended claims.

In the drawings, Figure 1 shows one form of my invention a plied to acompressed air rock drill, the cy inder of the latter being partiallybroken away, and together with the valve, being shown in longitudinalsection; Fig. 2 represents the same parts shown in Fig. 1, with thevalve and piston in a slightly different osition, and Fig. 3 is asection taken through t e engine at the tappet valve.

Referring to the drawings, a represents the l cylinder of a directacting engine employed in connection with the rock drill, the pistontherefor being shown at b, and the air chest at c. The compressed airenters the air chest, c, from the source of supply not shown, through anappropriate air inlet, d, and is controlled in its passage to theopposite ends of the cylinder, a, by the slide valve, e, of ordinaryconstruction.

To effect suitable control of the slide valve,

. e, there areprovideduponthe piston, b, ap ropriatelysha ed inclinedsurfaces, f, f,w ich are adapte during the reciprocation of the piston,alternately to enga e the opposite ends ofthe slidable segmenta valveactuator,

g, the latter being provided with an upwardly projecting tooth-engagingportion entering t e inner face of the slide valve, e, and

contacting on either side with suitable and preferably tooth-shapedengaging surfaces to impart a movement to the valve corresponding to thereci rocatingmovement of the piston. The va ve and the segment may beprovided with any desired number of any engaging teeth, although for simlioity I prefer in practice to employ the sing e tooth shown upon thesegment, and the surfaces of these teeth may be shaped either accuratelyto give correct rolling contact between the engaging surfaces, or withany ldesired degree of approximation.

To provide suitable guide-Ways for the sliding segment g, I may andpreferably do form a in the s ape of an arc to afford appropriatelyshaped inner guide walls for the segment, the outer or upper guide wallsof the se mental groove being formed by the materia of the valve late,i, secured to the cylinder and so shapedD as to enter appropriatelyformed recesses therein.

The construction illustrated wherein the segmental guide Walls areformed partly by the cylinder and partly by the va ve plate,

rovides an accurate and efficient guide-way or the segments, and yetincreases greatly the simplicity of construction, since the removal ofthe valve plate from the engine cylinder leaves the segment, g,unattached to any part and free to be withdrawn. The provision of theinner guide-way, h, is superior and preferable to those constructionswhere the cylinder is entirely cut away to replortion, h, in the Wallsof the cylinder ceive the tap et member since it materially strengthenst e cylinder atthat oint.

I have here shown the slide va ve, e, as provided with a suitablebalance plate, j, springpressed by the s ring, k, against the back ofthe valve, e, ten ing to reduce the load upon the valve and the frictionimpeding its movement.

In Fig. 1, the valve, e, is shown in its central position where no aircan be admitted to either end of the cylinder. To start the engine inoperation When the valve is in this position, the piston is first movedoff center 1n one direction or the other to throw the valve away fromits central position, as for example, to the left of the position shownin Fig. 1, and to that shown in Fig. 2. Air then passes from the airchest under the valve and 1nto the port, l, passing to the left hand endof the cylinder as viewed in the drawin s, causin the iston to travel riht-handed y until t of the segment, whereupon the upward slidingmovement oi' the latter forces the valve to the right opening the oposite port, m, to the air chest, and the port, lto the chamber, o,through which the exhaust passes through an appro riate outlet iminging. upon the tooth of t e segmental valre actuator g and .tending toforce the same in the direction of the passage ofthe exhaust. The pistonthus started in operation, obviously maintains its reci rocatorymovement as long as desired.

e se ment and its guides are preferably so shapec as to bring the centerof oscillation on the opposite side of the ath of travel of thereciprocating piston walls which engage the segment ends, the center ofoscillation 1n the engine illustrated practically intersecting the axisof the piston. This relation between the segment, its center ofoscillation and the tap et surfaces, f, f permits a very quick initiai)movement to be given to the valve and eliminates much unnecessaryfriction at the engaging surfaces as compared to osclllate a out an axlsoutside the cyllnder Walls.

B the provision of a sliding se ment directly engagin the walls of the s1de valve itsel without t e interposition of connecting links, journalmembers or the like, there is produced a tappet motion reduced to buttwo operative movm parts adapted Vto transmit directly to the va ve thereciprocatory movement of the piston, which transmission, inasmuch asthe same is through the instrumentality of the segmental gear alone, maybe made as accurate and correct as desired by roperly shapin theengaging toothed suraces. The toot ed segment, g, requires no additionalfastening device other than the simple co erating guiding walls of thecylinder and t e valve plate, and is therefore readily removablealthough being at all times accurately and effectively controlled in itsmovements. This construction also provides in a very simple manner,means for bringin the center of segment oscillation Within t e cylinderwalls.

It is to be understood that my invention is not restricted to the meredetails of construction, and form and arran ement of arts hereinpresented, the same eing submltted for illustrative pur oses only, butthat the same may be wide y'modified without departing from the spiritthereof.

Claim- 1. The combination with a cylinder, a iston therein, a valveplate, and a sliding va ve 65 controlling ports which open into thecyline inc ine f strikes the epressed end I with prior ta pet memberspinned or pivoted r l der at the opposite ends of the piston, saidpiston having oppositely arranged tappets, l the wall of the cylinderhaving a segmental groove or channel formed therein and disposedlongitudinally of the piston, a segmental valve actuator' seated in saidsegmental f' groove of the cylinder Wall with its ends projecting intothe path of movement of the tappets on the piston, the inner face ofsaid valve plate having a segmental groove or channe therein, wherebythe said late may be seated upon said segmental va ve actuator, thelatter being guided in its movement between the cylinder wall and saidvalve plate, and said actuator having a tooth in engagement with thesliding valve to reciprocate the latter.

2. The combination with a cylinder, a piston therein, a valve plate, anda sliding valve controlling ports which open into the cylinder at theopposite ends of the piston, said piston having oppositely arrangedtappets, the wall of the cylinder having a segmental groove or channelformed therein and disposed longitudinally of the piston, a segmentalvalve actuator seated 1n said segmental groove in the cylinder wall withits ends projecting into the path of movement of the tappets on thepiston, the inner face of said va ve plate having a segmental groove orchanne therein, whereby said late may be seated upon said segmentalvalve actuator, the latter being guided in its movement between thecylinder wall and said valve late, said segmental groove or channel in te inner face of the valve plate being. enlarged to form a chamberthrough which the exhaust may pass to a suitable outlet, said actuatorhavin a tooth in engagement with the sliding va ve to reciprocate thelatter.

3. The combination with a cylinder, a piston therein, a valve plate, anda sliding valve controlling ports which open into the cylinder at theopposite ends of the piston, said piston having oppositely arrangedtappets, the wall of the cylinder having a segmental groove or channelformed therein and disposed longitudinally of the piston, a seginentalvalve actuator seated in said segmental roove in the cylinder Wall withits ends pro- Jecting into the path of movement of the tappets on thepiston, the inner face of said valve late havin a segmental groove o1'channel) therein, w ereby said late may be seated upon said se mental vave actuator, the latter being gui ed in its movement between thecylinder wall and said valve plate, said segmental groove or channel inthe inner face of the valve plate being enlar ed to form a chamberthrough which the ex aust may passv to a suitable outlet, said actuatorhav- 1n a tooth 1n engagement with the sliding va ve to reciprocate thelatter, the said tooth being seated 1n said chamber, whereby the ex-lhaust may impinge directly thereon.

cylinder, a pispiston having oppositely arranged tappets,

said valve plate having a chamber formed therein in communication withthe exhaust,

the wall of said chamber being rovided with` a segmental groove orchanne a segmental valve actuator seated in said segmental groove orchannel and contacting with the walls thereof and having a sliding valveengaging tappet extending into said chamber and adapted to be impingedupon b f' the exhaust, the main or body portion o said valve actuatorbeing shielded from the impact oit' the exhaust by the wall of saidgroove or channel.

5. A drill of the character described comprising a casing provided witha cylinder, a slide valve controlling the motive power entering saidcylinder, a iston working in said cylinder, and a slida ly supportedrocker provided with an integral arm engagin said valve, and againstwhich arm the ex iaust impinges to hold the rocker against movementuntil the piston completes its stroke.

6. A drill of the character described comprising a casing provided witha cylinder, a piston working in said cylinder, a valve seatmg carried bysaid casing, aslidably supported rocker provided with an integral arm aainst which the exhaust impinges to hol the rocker against movementuntil the piston completes its stroke, and a slide valve engaged by thefree end of said arm.

7. A drill of the character described comprising a casing provided witha cylinder, a piston working in saidcylinder, a valve seating carried bysaid casing, a slide valve controlling the motive power entering saidcylinder, and a slidably mounted rocker having an integral arm connectedto said valve, said arm being located in a recess in the valve seatingforming a part of the exhaust outlet, whereby the exhaust will impingethereagainst to hold the rocker against movement until the pistoncompletes its stroke.

8. A drill of the character described comprising a casing provided witha cylinder, a piston working in said cylinder, a valve seating having achamber therein forming part of the exhaust outlet, a slidably mountedrocker having an arm extended into said chamber, and against which theexhaust impinges to hold said rocker against movement until the pistoncompletes its stroke, said rocker being also provided with arms forengaging the piston, and a slide valve controlling the motive powerentering said cylinder, said valve being connected to the firstmentioned arm of said rocker.

9. A drill of the character described comprising a casing provided witha cylinder, said casing having an exhaust outlet, a piston workingtherein and provided with an annular reduced portion forming shoulders,a slidably mounted rocker having curved arms for engaging the shoulderson said piston, said rocker having a vertical member located in saidexhaust outlet, and against which the exhaust impinges to hold saidrocker against movement until the piston completes -its stroke, and aslide valve connected to said vertical member and controlling the motivepower entering said cylinder.

10. The combination with a cylinder, a piston therein, a valve plate,and a sliding valve controlling ports which open into the cylinder atthe opposite ends of the piston, said piston having oppositely arrangedtappets, the wall of the cylinder having a seg'- mental groove orchannel formed therein and disposed longitudinally of the piston, asegmental valve actuator seated in said segmental groove of the cylinderwall with its ends projecting into the path of movement of the tappetson the piston, the inner face of said valve plate having a segmentalgroove or channel therein, whereby the said plate may be seated uponsaid segmental valve actuator, the latter being guided in its movementbetween the cylinder wall and said valve plate, and an outturned toothedvalve actuating arm carried by said actuator and engaging acorrespondingly shaped recess in the inner face of said slide valve,said toothed arm and said recess being properly shaped to afford rollingcontact between the same and thereby to reduce the friction between thesaid valve and the said arm.

l1. The combination with a cylinder, a piston therein, a valve plate,and a sliding valve controlling ports which open into the cylinder atthe opposite ends of the piston, said piston having oppositely arrangedtappets, the wall ofthe cyllnder having a segmental groove or channelformed therein and disposed longitudinally of the piston, a segmentalvalve actuator seated in said segmental groove of the cylinder wall withits ends projecting into the path of movement of the tappets on thepiston, the inner face of said valve plate having a segmental groove orchannel therein, whereby the said plate may be seated upon saidsegmental valve actuator, the latter being guided in its movementbetween the cylinder wall and said valve plate, and means between thevalve and the actuator for causing movement of the former through themovement of the latter, said means comprising a toothed arm secured toone member and a correspondingly shaped recess formed upon the othermember, said toothed arm and recess being so shaped as to provide forrolling contact between the same, thereby to reduce the friction to aminimum.

12. In an apparatus ofthe class described, the combination with thecylinder a, the

ln testimony whereof, I have signed my name to this specific-anon, 1nthe presence 0f two subscribing witnesses.

DANIEL J. OROURKE.

W'itnQSSQS A J. ,DUNCAN UPHAM, THOMAS M. HEY.

